Barcelona's David Villa is congratulated by team-mates after his late equaliser saved a point against Sporting Gijon. Barça's only league defeat this season came at home to Hercules in September. Photograph: Alvaro Barrientos/AP

Let misanthropes rejoice. Barcelona can go wrong, if only a little. Following Saturday's 1-1 draw at Sporting Gijón, the team have now won only six of the last 20 games that have followed a programme of international matches. There was splendour in any case at the weekend. Pep Guardiola's side were 1-0 down and there was no sense of inevitability about the equaliser with 10 minutes remaining.

It would be amusing to say that the team needed to scrap their way to a goal and Lionel Messi did indeed battle for possession, but once he had the ball the calibrated through pass was outdone only by the chipped finish David Villa sent over the head of the goalkeeper Ivan Cuéllar. The scorer had achieved little until then, but innate talent had its say. Arsène Wenger ought to have had feelings of admiration mixed with those of regret. His Arsenal side should never have got themselves into a contest this week that will delight a continent. Unlike the other English clubs, they came second in their Champions League group. Defeats at Braga and Shakhtar Donetsk have led Arsenal to a tie they would rather have delayed if it had to be endured at all. They also met Barcelona last year, coming from 2-0 down at the Emirates to draw 2-2 in the first leg of the quarter-final.

The return was lost 4-1, with Messi scoring all of Barça's goals. Arsenal, the one mildly plausible challenger to Manchester United for the Premier League title, are improving, but there have also been adjustments to Guardiola's side that heighten the idealism. He spent £34.2m to take Villa from Valencia last summer, although the forward will have turned 30 by the end of this year.

The manager had paid even more for Zlatan Ibrahimovic in 2009. Despite his great efficiency as a striker, the Swede did not look complementary to the streamlined Barcelona style. Having fallen out with Guardiola, Ibrahimovic, scorer of both goals at the Emirates last year, is now on loan to Milan. The effect has been to make Barcelona attack with an even greater purity.

Ideas for stopping them can soon seem misguided. It is a modern habit to press when the opposition approach, but Barcelona are sure of themselves while encountering that sort of supposed confrontation. They are very likely to retain the ball and send someone into the space behind players who have pushed up too far. If there is any answer to them at all, it is an old-fashioned one.

When Barcelona failed last season in the defence of the European Cup, they came up against an Internazionale line-up in the semi-finals that had a touch of1960s' catenaccio about it. Rather than press, the Serie A side sat deep. Even so, eachfootball match has its own quirky individuality and Barcelona did open the scoring that night before Inter responded with three goals and then coped well enough with the return.

The visitors, although they made light of the matter, had been obliged to go to San Siro by road because the volcanic-ash problem of the time prevented them from flying. Little was in their favour and least of all the identity of the opposition's manager, who went on to get the better of Bayern Munich in the final. José Mourinho is now in command at Real Madrid. His side were trounced 5-0 at Camp Nou in November, but that may simply tell us that he needs more time to school his players, as he did Inter. By beating Espanyol with 10 men on Sunday they appeared to be responding.

Despite Mourinho's scheming to establish a dominant Real we could still come to see the present Barcelona as a team for all-time, fit to stand beside those whose feats are treasures that belong to everyone who cares to recall them. The side may yet be bracketed with the Real Madrid of the European Cup's early days, with Fabio Capello's Milan team that trounced the 1994 Barcelona in the final or, most aptly, with the total football of Ajax, who won it in three consecutive years from 1971.

The parallels can become warped because this is another era, one in which players keep their next move in mind and clubs have to sell stars before they walk away as free agents. It is a tribute to the millionaires of Barcelona that when they are on the field the only wealth that anyone cares about is the opulence of their gifts.